Electrical apparatus



Jan. 1, 1929. 7 1,697,418

H. H. DOW

ELECTRICAL APPARATUS .Origiaal Filed Jan. 1927 INVENTOR.

ATTORN Y6 Patented Jan. 1,1929.

UNITED STATES "PATENT OFF HERBERT H. now, or MIDLAND, MICHIGAN,

PANY, or MIDLAND, MICHIGAN,

ICE." C

Ass GnoR O THE now CHEMICAL COM- A CORPORATION or -MIGHIGAN.

ELECTRICAL APPARATUS.

Application filed January 5,1927, Serial No. 159,084. Renewed November 17, 1927.

- To the accomplishment of the foregoing.

and related ends, the invention, then,'consists of the features hereinafter fully disclosed, and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail but one of the various ways in which the principle of the invention may be employed. 5 In said annexed drawing, the sole figure is a Vertical sectional View embodying the. invention.

The casing 1, ordinarily with ribbed or corrugated wall contour to present a maximum 2 of radiating surface, contains the transformer windings 2 and core 3. The detail of the core, and the bushings and leads through and the details of the windings may the case,

p be varied as individual requirements dictate, but between the casing and windings there -is rovided a dielectric liquid comprising a sta le aryl or aromatic organic compound. Diphenyl oxide, for example, while presentving excellentcharacteristics in a dielectric sense and also as a heat transfer medium, of itself has a freezing point or temperature of solidification of-about 27 6., which is such as to be disadvantageous in cold climate usage. By modifying the diphenyl oxide with an 40 agent for lowering the freezing point, the desirable properties are retained while at the same time a range of availability adaptable to cold climate usage is had. As such agents, I have found that chlorinated hydrocarbons, particularly carbon tetrachloride, are effective and advantageous. carbon tetrachloride for instance may be used, and the freezinglpoint can be regulated as desired. A composition of diphenyl oxide and carbon tetrachloride 20% shows initial crystal formation at a temperature of 16 C. The crystals formed float freely in the menstruum of'remaining liquid, and it is only as the temperature is reduced further to 2 C. that solidification occurs. Diphenyl windings can result.

of a construction From 10 to 30% of' oxide for instance, on melting expands considerably, and as a safeguard in the event that the transformer be subjected to very low temperatures with the current off, and the dielectric liquid should solidify entirely, I provide for melting at the surface first as the current is put on. Pressure from internal melting under a hard crust is thus avoided and, consequently, no damage to case or For such surface melting, I arrange a portion of the transformer I that will heat up quickly, near or through the surface either as a special projection or a portion of the core as such, or an additional resistance heater. In this manner, when the current is put on, the heating projection will melt the surface of. the dielectric first and there is no opportunity for internalpressure with any dielectric filler that may be used having such tendency to expand when melted.

Other modes of applying the principle of the invention maybe employed, change being made as regards the details disclosed, pro yided the means stated in any of the follow- 1ng claims, or the equivalent of such, be employed. V

I therefore particularly point out and distinctly claim as my invention In apparatus of the character described, the combination of a casing, transformer windings and core, and a dielectric liquid between said casing'and windings, said liquid as a projection of the dielectric,

comprising an arvl compound and an agent for lowering the freezing point. 1

2. In apparatus of the character described, the combination of a casing, transformer windings and core, and a dielectric liquid between said casing and windings comprising an aryl compound and an agent for lowering the freezing point, a projection of said core extending in the region of the surface of said liquid. I L

3. In apparatus of the character described, the combination of a casing, transformer windings and core, and a dielectric liquid be-v tween said casing and windings, said liquid comprising diphenyl oxide and an agent for lowering the freezing point.

. 4. In apparatus-of the character described, the-combination of a casing and conductors therewithin, a dielectric liquid between said casing and conductors, and means for melting the surface portion of the dielectric prior to the deeper portion, after freezing.

v '5. In apparatus of the character described,

the combination of a casing and transformer .windings and core, and a dielectric liquid between said casing and windings comprisrachloride. 1

ing diphenyl oxide and an'agent for lowering the freezing point, a projection of said core extending out'of said liquid.

6. In apparatus of the characterdescribed,

the; combination of a casin transformer windings and' core, and a dlelectric liquid between said casing and windings, said liquid comprising 'diphenyl o'xid'e'and carbon tet- 7 In apparatus of the character described,

the combination of a casing, transformer Y .8. In electrical apparatus, the combination of a normally liquid dielectric comprising an aryl compound and a-smaller proportion of an agent operating against freezing th of as a coherent mass, and electric conductors therein. e t

, 9. In electrical apparatus, the combination of a normally liquid dielectric comprising diphenyl oxide and a smaller proportion of an agent'operating' against freezing thereof as a coherent mass, and electric conductors therein.

' 10'. In electrical apparatus, the combination of a normally liquid dielectric comprising an aryl compound and an organic chlor compound, and electrlcgconductors therein.

11. In electrical ap aratus, the combination of a normally liquid dielectric comprising diphenyl oxide and an organic chlor compound, and electric conductors therein.

Signed by me this 24 day of December,

HERBERT H. Dow. 

